Oil sands are growing in importance as a source of petroleum. Oil sands are found in various parts of the globe, but the most significant deposits occur in northern Alberta, Canada, along the Athabasca River. The composition of oil sands is a mixture of quartz, clay, water and about ten percent heavy oil with a consistency of tar and known in the industry as bitumen.
The accepted practice for extracting bitumen from oil sands is to mix the sands with hot water and caustic to form an oil emulsion that is siphoned off from the solids. The mineral tailings are discarded after about 95 percent of the oil has been recovered. The extracted oil is upgraded by one of two processes to produce a synthetic crude oil that is suitable for refining at a later stage.
While current technology is workable, it has some drawbacks, particularly as practiced on a large scale. Water pollution is caused by the discharge of substantial quantities of wastewater. The energy efficiency of the process is poor. Lastly, the required investment in plant and equipment is considerable.
The object of the present invention is to provide an improved bitumen extraction process which is more cost-effective, meets environmental concerns and provides a product of the highest quality. This object, as well as other features and advantages of the present invention, will be apparent from the following description which is based on the single drawing FIGURE that is included.
Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawing.